1. Technical Field of the Invention
The object of the present invention is a device for marking the position of automatic transmission gearshift lever arms of automobile vehicles, being of the type which employs a lit-up marker to show the user the possible positions which the lever can take up and, by means of extra lighting, the selected or working position of the lever.
2. Prior Art
Known in the art are an extensive variety of embodiments of devices for marking the selectable positions of automatic transmission gearshift lever arms and the position selected by the user or working position. In general, the known embodiments of marking devices such as those cited are fitted to the support of the gearshift lever and include, on the external cover of the support which is traversed by the lever arm, a plurality of translucent marking plates of relatively small dimensions whose number and layout correspond with the positions in which the user may situate the lever arm, each marking plate being provided with a corresponding graphic sign to show the working speed of the gearbox. Mounted inside each of the marking plates are means of lighting powered by the battery of the vehicle and permitting the graphic sign on the plate to be seen. In order to achieve brighter lighting of the marking plate for the working position of the lever, the known embodiments of marking devices include means of extra lighting which are in general based on the reflective properties of a specular surface in order to achieve, by means of reflection of the incident light beam coming from the corresponding means of lighting, an extra lighting of the marking plate which thus differentiates it from the other adjacent marking plates. Such means of extra lighting by reflection essentially include a prismatic body provided with a reflective surface which is attached to the lever arm in such a way that both, arm and reflective body, take up the same relative position independently of the working position of the lever.
In general, the means of extra lighting which use a reflection surface coupled to the lever arm present the following main disadvantages: a) the extra lighting of the translucent plates is dependent upon the state of the reflective surface which, due to environmental conditions, may vary, reducing thereby the reflective capacity of the incident light beam and in consequence reducing the level of extra lighting of the plates; b) the fact that the reflective surface is attached to the lever arm in such a way that both take up the same relative position, together with the limitations presented by the path of the reflected light beam, imposes a certain layout of the marking plates, which layout consists specifically in situating the marking plates in positions substantially parallel to the travel of the lever arm; and c) the intensity of the extra lighting of the marking plates is difficult to adapt to the needs of each specific case of application and is even, under certain circumstances, insufficient.